Will smudger come back on thomas the tank engine on season 13?

Answer 1

Most likely not.

In his initial appearance, Smudger's television series model was simply Rheneas's model painted green, renamed with a different face. As the series is now rendered in CGI, it's not much of a problem anymore, but the similarities between the two engines would be easy for the audience to notice.

Also, Smudger was locked away in the back of a shed, and the railway was later closed down and filled with overgrowth. There would have to be a long explanation as to how Smudger is still alive today, perhaps having him be rescued before his line closed and have him move to another railway.